<?php
/**
 * Created by PhpStorm.
 * User: wyq
 * Date: 2022/2/7
 * Time: 16:05
 */

/**
 * @param Integer $a
 * @param Integer $b
 * @param Integer $c
 * @return String
 */
function longestDiverseString($a, $b, $c)
{
    $arr = [
        'a' => $a,
        'b' => $b,
        'c' => $c,
    ];
    $i = $code =  0;
    while (true) {
        $arr = arsort($arr);
        if ($arr < 1) break;

    }
    return $res ? implode('', $res) : '';
}
$res = longestDiverseString(1, 1, 7);
var_dump($res);